1. Field of the Invention
The present invention relates to a magnetic recording and reproducing apparatus, such as a videotape recorder, of the type in which a magnetic tape wound on reel hubs received in a cassette is pulled out of the cassette and is caused to travel while contacting a rotary head drum installed outside the cassette, thereby recording or reproducing signals.
2. Description of the Prior Art
In recent years, magnetic recording and reproducing apparatus, such as a cassette type videotape recorder, have been reduced in size and weight. In order to make the mechanism simple, it is consequently general practice to employ separate drives for the following respective means: means for pulling out a magnetic tape from a cassette and winding the tape around a magnetic head such that the tape travels while passing over the head; means for changing over various operation modes from one to another when the tape is running; and means for pressing a pinch roller against a capstan.
The arrangement of a prior magnetic recording and reproducing apparatus will be described hereinunder with reference to FIGS. 1 and 2. First, when a cassette 1 is loaded, tape guide posts 2a, 2b, inclined posts 3a, 3b and a pinch roller 4 are positioned inside the loop of a magnetic tape 5 which is passed in the manner shown by the two-dot chain line in FIG. 1. Then, when the loading of the cassette 1 is detected by a switch (not shown), a loading motor 6 is rotated, and the rotation of the motor 6 is transmitted to a worm wheel 8 which is meshed with a worm 7, whereby a loading ring 10 (see FIG. 2) is rotated counterclockwise through a pinion gear 9. On the other hand, a loading ring 11 is rotated clockwise by a dual gear 12 which is meshed with the pinion gear 9. A base 13a mounting thereon the tape guide post 2a and the inclined post 3a thereon is connected to the loading ring 11 by a rod 18a, while a base 13b mounting thereon the tape guide post 2b and the inclined post 3b is connected to the loading ring 10 by a rod 18 b. In consequence, the magnetic tape 5 is gradually pulled out of the cassette 1 by the leading tape guide posts 2a and 2b. The magnetic tape 5 having thus been pulled out is wound around the peripheral surface of a rotary head drum 14 and is thereafter fixed in this position. Then, when the operation mode is changed over to the recording or reproducing mode, a plunger 15 is actuated to pivot a pinch lever 16 equipped with the pinch roller 4 in the clockwise direction, thereby pressing the pinch roller 4 against a capstan 17 to permit the magnetic tape 5 to travel at a constant speed for a desired recording or reproducing operation. In the drawings, reference numerals 19 and 20 respectively denote holders for the pinch lever disposed between the plunger 15 and the pinch lever 16; numeral 21 a compression spring disposed between the holders 19 and 20; numeral 22 tape guides provided on the cassette 1; and numerals 23 and 24 supply and take-up reels, respectively, provided on the cassette 1.
Thus, with the prior arrangement, separate drives are used for each of the various means, that is, the means for pulling out the magnetic tape from the cassette and winding the tape around the magnetic head such that the tape travels while passing over the head, a brake means (not shown) for applying brakes to the reels in various modes when the tape is travelling, and the means for pressing the pinch roller against the capstan. Such an arrangement realizes reduction in size of the apparatus to a certain extent as a result of the simplification of the mechanism. However, further reduction in size of the apparatus is unfavorably limited with the prior arrangement. Additionally, the employment of separate drives for the respective means disadvantageously causes a higher cost and an increase in weight of the apparatus as a whole. On the other hand, a prior magnetic recording and reproducing apparatus in which respective operating means are actuated by separate drives requires a disadvantageously large space to accommodate a mechanism for changing over the actuating means from one to another, which fact constitutes a great handicap in the quest to reduce the size of the apparatus.